General :: Captivate Locked But In Reboot Loop

i just got a Samsung Captivate Galaxy S I9000, here is the problem.

1) It is locked to Rogers Wireless, because my friend tested it by inserting his Rogers SIM card into it and it works normally like a phone.

Here is where it gets interesting:

2) When i insert another foreign SIM card such as FIDO cell carrier. The phone boots into the lock screen and it says Media Scanning...and then it proceeds to the booting up screen again.

From my lack of skills in Android software, i am really stuck. But from the powers of observation, it seems the phone was flashed and is currently running a custom ROM on it from Serendipity VII.

The phone runs perfectly, without a sim card, but that's like holind a tablet without a phone line. What should i do?

Here are some details on the phone's systems.

-Firmware version 2.3.3

-Model Number:I897 ????(Why does the boot screen show I9000?,custom Rom?)

-Build number: Serendipity VII Build 2